Motor controller



July 24, 1923.

T. E. BARNUM MOTOR CONTROLLER Filed July 50 17 2 Sheets-Sheet 1 Www July 24, 1923. 1,462,476

T. E. BARNUM MOTOR CONTROLLER Filed July 30, 1917 2 Sheets-Sheet 2 Patented July 24, 1923.

UNITED STATES PATENT OFFICE.

THOMAS E. BARNUM, OF IMILWAUKEE,

"WISCONSIN, ASSIGNOR TO THE CUTLER- HAMMER MFG. 00., OF MILWAUKEE, -WISCONSIN, A CORPORATION OF WISCONSIN.

MOTOR CONTROLLER.

Application filed July 30,

T 0 all whom it may concern Be it known that I, THOMAS E. BARNUM, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Motor Controllers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to controllers particularly adapted for the pump motors of pneumatic tube systems, although controllers embodying the invention may be advantageously used in other relations.

In such systems it is desired to start the pump motor each time a cylinder is placed in a tube and to automatically stop the motor after operation thereof for a predetermined time, and the present invention has among its objects to provide a Simplified, efficient and reliable controller for this and other purposes.

A further object is to provide a time element controller of the aforesaid character, governable by a single electromagnet and one providing for self-retiming under con ditions to be hereinafter set forth.

Other objects and advantages will hereinafter appear.

The accompanying drawing illustrates one embodiment of the invention and the same will now be described, it being understood that the embodiment illustrated is susceptible of various modifications without departing from the scope of the appended claims.

In the drawing,

Figure 1 is a front elevation of the controller;

Fig. 2 is a side elevation of Fig. 1.

Fig. 3 is an enlarged detail view of a contact device shown in Fig. l; and,

Fig. 1 is a diagrammatic view of one circuit arrangement for the controller.

Referring to Fig. 1, the controller includes a double pole main switch 1, an electromagnet 2 having an armature 3 operatively connected to said switch and adapted when at tracted to close the same, means including a latching pawl 4 for locking said switch in closed position subject to release upon return of the armature 3 to initial position and a dash pot 5 for retarding sucn return movement of the armature. Also, the con- 1917. Serial No. 183,474.

troller includes an auxiliary contact arm 6 and a co-operating contact 7 normally in engagement and the former being disengageable from the latter by the armature 3 when attracted. Certain of these elements are mounted upon a frame 8 secured to a panel 9 and other of the same are mounted directly upon said panel.

The switch 1 comprises a pivoted plate 10 carrying contact arms 11 and 12 to respectively engage contact studs 13 and 14 fixed to the panel, each of said arms being insulated from said plate. More specifically, each contact arm is directly mounted upon an undivided bearing plate 15 (Fig. 2) fixed to but insulated from the plate 10 as by insulated rivets 16 and each of said bearing plates provides for its respective contact; arm an open pivotal bearing 15 and stop 15*. Also, each bearing plate has attached thereto a spring tension device 17 to engage its respective contact arm for yieldingly holding the latter against the stop in the former and for placing said arm under tension when moved by plate 10 into engagement with its respective contact. The plate 10 is pivotally mounted upon a rod 18 supported at one end by the frame 8 and at its other end by a bearing member 19 fixed to the panel 9 and said plate has a downwardly extending arm 10 connected by a tension spring 20 to a member 21 fixed to the panel whereby said plate is biased outwardly to disengage the switch contacts. Also, the plate 10 is provided with an upwardly extending lug 10 to abut a fixed part, hereinafter described, for limitation of the outward movement of the former and with an integral arm 10 extending outwardly for actuation by the armature of the electromagnet.

The electromagnet 2 is of the alternating current type and is provided with an inverted U-shaped magnet frame 22 (Fig. 2) which is bolted to an outwardly projecting lug 8 of the frame 8 and the winding of said electromagnet is mounted upon the outer leg of said frame. The frame 22 is formed of laminations and the leg thereof forming the core of the winding, is provided with a shading coil 23. Also, the armature 3 of said electromagnet, which is pivotally supported by the rod 18 (Fig. 2) is formed of laminations and provided with rigid extensions 3 for connection to the dash pot a point.

and with rigid lateral extensions 3 and 3 (Fig. 1). Further, the armature is provided with a transversely extending top plate 3, suitably secured as by rivets lo the extensi ons 3 and 3 said plate projecting beneath and engaging the extremity of the actuating arm 10 of switch 1. Thus when the armature is attracted by the electromagnet it rocks the arm 10 upwardly thereby rocl'ing the plate 10 inwardly and closing switch '1.

The latching pawl i is pivotally supported by a pin ea carried by a bifurcated portion of the switch actuating arm 10 and is biased by a spring 25 connecting the same with a lug 1O on plate 10, to engage a stop 26 when the switch 1 is closed. This provides for locking the switch in closed position and the stop 26 is carried by a lever 27 which is operable to rock said stop to release the pawl l therefrom. More specifically the lever 27 is pivotally supported by a pin 28 carried by a bracket 25) projecting from the panel 9 and the stop 26 is carried upon said lever directly above its pivot Further, the lever 27 is provided with. a spring 30 connected at one end to an upwardly extending lug 27 thereof and to a lug 29 on the bracket 29. Thus said lever is biased to place th stop 26 in an effective relation with respect to the latching pawl, the biased movement of the lever beinglimited, by a. second lug 27 thereon co-operating with a second lug 29" of the bracket 29. On the other hand, the lever 27. carries at its outer end a roller 31. disposed beneath a set screw 32 threaded through the extensions 3" and 3 of the armature and upon release oi? the armature said set screw is adapted to strilre said roller thereby rocking the lever 27 against the bias, of spring 30. This in turn rocks the stop 26 to release the latchingpawl 4 thereby permitting the switch 1 to open. In this connection it is to be noted that adjustment of the set screw enables variation of the range of movement of the armature required to trip the latching pawl and hence provides for a certain degree of regulation of the time element of the controller.

The dash pot which is of a conventional single acting type, has its casing bolted to the extension 8? of the vtrame 8 and has its piston connected to the extension 3 of the armature to retard downward movement of said armature. Thus the dash pot serves to retard tripping of the switch 1 upon deenergiz'ation of the electromagnet and with a given range of movement of said armature said dash pot gives a definite time element to the controller.

The auxiliary contact arm 6 of Fig. 1 is mounted upon a lever. 33 3) ful crumedzupon a stud 34 carried by the, frame 8 and said lever has a forwardly extending lug 33" bearing upon the extensions 3 of the armature 3. Thus when the armature is attracted it hits the extension 33 0t lever 5&5, thereby disengaging; contact arm (5 from contact T. \i'hereas a spring connected to said contact arm and to a member [56, lixed to the panel 9, serves to bias said arm to contact 1' when the armature is released and to bias said armatur to trip the locking means as described. This contact arm. and its co-opcratin contact may e utilized a" hereinafter set forth, to ins rt a resistance in circuit with the electroinagnet upon cnergization thereof.

Binnmarizing the operation of the controller, cnergization oi the electromagnet causes the armature to clos switch 1 and disenga the auxiliary contacts 6 and i' and ereupon the latching pawl locks the switch in closed position. Then it the electromagnet be de-energiZeil the armature is released, and. subject to retardation by the dash pot. trips the switch 1 which thereupon opcns under the influence oi." return spring 2t thus i n'eparing the controller for another operation.

For retention oi the switch 1 in closed po sition for a prolonged period the controller further provided with a member 37 (Flo. adapted to be set in the pathot a lug 2N on the lever f2? to prevent actuation o l said lever by th armature. The member 87 comprises a rod reciprocable in a liiearing provided in the bracket 29 and said member has an encircling spring 38 interposed be: tween a collar 39) thereon and the rear end oi said bearing. The spring thus serves to retract the member I-li' from obstructing re lation with respect to the lever 27 whereas sa d member is provided at its forward end with a hooked extension adapted upon oscillation to be engaged with the trout lace oi? its bearing" to retain said member in the path of lever 27.

Peter-ring now to Fig. l. the same shows the controller schematically and as employed to control a. three phase alternating current motor M. The switch 1 is shown as controlling circuit between the motor and two lines of the supply circuit L, L L while the auxiliary contacts 6 and 7 are shown as controlling a. resistance '1 for the electromagnet Also, this figure schemati (ally illustrates a switch 41:0 for controlling the circuit oi the electromagnet, said switch tending to normally remain in the position shown and representing the: circuit closing means oi a pneumatic tube system.

ith the controller in normal position, closure of switcl. l0 completes circuit from line If by conductor ll through said switclr by conductor e2 through auxiliary contacts {5 and T, by conductor 4;?- through the clectromagnet 2. by conductor M; to line L This provides for energization. of the electromagnet to close switch 1 thereby completing circuit from line L through contacts 13 and 11 to one terminal of the motor and from line L through contacts 14 and 12 to a second terminal of the motor. The third terminal of the motor is directly connected to line L and hence upon closure of switch 1 the motor M is set in operation and continues to run until the elec tromagnet is de-energized by switch 40 and the armature is returned to initial position to trip switch 1. Also, upon operation of the controller by the electromagnet auxiliary contact arm 6 is disengaged from contact 7 to include the resistance 1' in circuit with the electromagnet for protection thereof in case of continued energization thereof by a short circuit or otherwise.

Thus assuming but a momentary closure of the circuit of the electromagnet, as in pneumatic tube systems, the controller provides for operation of the motor for a given time and for automatic disconnection of the motor from circuit thereafter. On the other hand, should the circuit of the electromagnot be re-established prior to return of the controller to initial position, said controller would again operate without interruption of the motor circuit and retime itself for the given minimum period of operation of the motor.

What 1 claim as new and desire to secure by Letters Patent is:

In a motor controller, in combination, a starting switch having an oscillatable contact member, mechanical means for locking said switch in closed position, said means including cooperating latching elements respectively pivoted on said contact member and a fixed support, an electromagnet having an attractable part adapted when attracted to actuate said oscillatable contact member to close said switch and when released to actuate one of said latching elements to release said switch, and means for retarding movement of said attracted part when released.

in a motor controller, in combination, a starting switch having an oscillatable contact member, mechanical means for locking said switch in closed position, said means including a pawl pivoted on said contact mem ber and a co-operating latching element pivotally mounted on a fixed support, an electromagnet having an attractable part adapted when attracted to actuate said contact member to close said switch and when released to grip said latching element to release said switch, means for retarding movement of said attractable part when released, and means adapted to be set to lock said latching element against tripping thereof.

23. In a motor controller, in combination, a panel, a switch mounted thereon, said switch having an oscillatable contact member provide d with an extension projecting outwardly from said panel, a magnet frame mounted on said panel contiguous to said switch, an electromagnet mounted on said frame and having a pivoted armature projecting outwardly from said base and engaging said extension of said switch whereby said electromagnet is energizable to actuate said contact member for closure of said switch, mechanical means to lock said switch in closed position, including an oscillatable member having a part projecting outwardly from said panel to be engaged by said armature for release of said switch following de-energization of said electromagnet and dashpot mounted on the front of said magnet frame and connected to said armature for retarding movement of the latter when released by said electromagnet.

In witness whereof I have hereunto subscribed my name.

THOMAS E. BARNUM. 

